About This Fish

Species Name

Mangrove Jack

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About the Species

The mangrove jack (Lutjanus argentimaculatus) is also known as mangrove red snapper, Jack, Snapper, Creek Red Bream, Dog Bream, Purple Sea Perch, Red Bass, Red Bream, Red Perch, Red Reef Bream, River Roman, Rock Barramundi. It is a ray finned fish which belongs to Family Lutjanidae under Order Perciformes of Class Actinopterygii. It is found in the Indo-Pacific region from Australia in the south to Japan in the north and as far west as the eastern coast of Africa. The young fish is generally found in estuaries and rivers while the larger adult occurs on the outer reefs.

The mangrove jack has an elongated body and a wide, flat or oval, convex or slightly concave head. Back is generally greenish brown, grading to reddish on sides and ventral parts while juvenile has pale bars on the sides of the body and one or two blue lines are present on the cheeks. A parly mark is present in the centre of each scale which gives the appearance of cris-crossing lines on the body. It has wide mouth with conical teeth and sunken face. Dorsal fin is divided into spiny and soft parts; spiny part has 10 spines while soft part contains 13-14 rays. Anal fin contains 3 spines with 7-8 soft rays and caudal fin is emarginated. Preopercular notch and knob are poorly developed. Fins have a pinkish shade with the tail generally a darker shade. Juvenile possesses a blue line below the eye. It is mainly nocturnal fish which consumes other fish and crustaceans such as crabs and particularly prawns. Spawning occurs during the summer months on deep offshore reefs with preferable salinity and temperature which ranges from 30-33 ppt and 5-320C respectively. It reaches sexual maturity at the age between 3 and 11 years at around 45-50 cm in length. It grows up to 150 cm in length and 16 kg in weight. It can live up to 32 years.